Functional shoe having spaced front and rear outsoles

ABSTRACT

The present invention relates generally to a functional shoe having spaced front and rear outsoles. More particularly, the present invention relates to a functional shoe having spaced front and rear outsoles, the functional shoe providing comfort to a user by being flexibly deformed to conform to a shape or walking form of a user&#39;s foot during walking, and guiding a tandem gait by allowing a front portion of the foot to be leaned inward while allowing an inside portion of the foot to be leaned inward at the moment when the foot contacts the ground during walking.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No.10-2018-0147460, filed Nov. 26, 2018, the entire contents of which isincorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to a functional shoe havingspaced front and rear outsoles. More particularly, the present inventionrelates to a functional shoe having spaced front and rear outsoles, thefunctional shoe providing comfort to a user by being flexibly deformedto conform to a shape or walking form of a user's foot during walking,and guiding a tandem gait by allowing a front portion of the foot to beleaned inward while allowing an inside portion of the foot to be leanedinward at the moment when the foot contacts the ground during walking.

Description of the Related Art

Due to industrial development, income levels have increased, and levelsof material wealth have increased significantly. However, people oftensuffer from lack of exercise, poor posture, and the like as poor livinghabits, leading to a new problem such as stress, adult illness, andobesity causing deterioration of quality of life.

In recent years, the interest in quality of life and health has emergedas a social concern, to the extent that a cultural trend called“well-being” has arisen. In this context, the interest in effectiveexercise methods, correction of poor posture, diet, and the like isincreasing.

On the other hand, the foot is a delicate human organ that forms acomplex, balanced structure composed of about 52 bones, one-fourth ofhuman body, and numerous joints, ligaments, nerves, and blood vessels,enabling walking. The foot structure is largely composed of tarsalbones, metatarsal bones, phalanges, and calcaneus, and the connection ofthese bones, ligaments, and nerves enables walking.

In particular, the profile line of the sole, from the heel of the footto the toes of the foot, is a part that serves to support the human bodyin a balanced manner with minimal energy consumption, and affects thespine or neck of the human body connected thereto. As such, the footplays a vital role in the human body and is often called “the secondheart”. During walking, the sole of the foot needs to rest for a longperiod of time in order to avoid stress to the body.

The ideal way of walking involves landing a foot on the heel, rollingonto a middle portion of the sole, and pushing off on the root of thebig toe. During this walking, the trajectory of weight applied to thesole starts at the valgus of the heel, passes over the middle portion ofthe sole, and is curved inward to move toward the big toe.

Humans typically wear shoes when walking. Shoes protect the soles andankles and play a vital role of protecting the knees and the spineagainst impacts generated due to the weight transferred to the groundduring walking.

However, due to lack of awareness by the general public, mostmass-produced shoes do not consider the shape of the foot, but onlyfocus on the appearance of the shoes. This causes problems such asdifficulty in walking, distortion of the human skeleton that causes painin the lower back and knees, and the like even when wearing shoes.

In an effort to solve such problems, functional shoes are emerging toallow a user to feel comfortable and suffer less impact during walkingby considering the shape of the foot or the form of walking. An exampleof the functional shoes is disclosed in Korean Patent No. 10-1008344(hereinafter referred to as “cited invention”).

The cited invention, which is proposed by the applicant of the presentinvention, provides a shoe having a shape in which an outsole, which isconventionally formed as an integral body from the toe to the heel, isdivided into a front outsole and a rear outsole spaced apart from thefront outsole. In particular, a middle portion of the shoe is configuredto bend easily, which makes the foot comfortable during walking.

In the case of the front outsole, which is a part to which a large loadof the user's weight is transferred during walking and thus is requiredto be more flexible compared to the rear outsole. However, the citedinvention does not have a configuration for this, and there is a problemin that the front part of the foot does not change actively in shapeconforming to the user's foot shape or walking form during walking.

In addition, it is common to see many people walking with an out-toedgait. Out-toeing refers to a condition in which when a person walks, hisor her feet are turned outward at an angle. In out-toeing, a person'slegs curve outward at the knees while walking.

When walking with an out-toed gait, it may be difficult to walk or runfor a long period of time due to a reduced driving force to move a bodyforward during running, flat feet get may be worsened, and toe diseasessuch as hallux valgus, calluses, and the like may be caused. Inaddition, risk of degenerative arthritis in adults may increase.Moreover, in an out-toed gait, as the back curves outward, the spinecanal may narrow, leading to inflammation of facet joints. This may alsolead to distortion of pelvis, causing musculoskeletal disorders of theback, such as back pain, lumbar disc disease, and the like.

The foregoing is intended merely to aid in the understanding of thebackground of the present invention, and is not intended to mean thatthe present invention falls within the purview of the related art thatis already known to those skilled in the art.

DOCUMENTS OF RELATED ART

(Patent document 1) Korean Patent No. 10-1008344 (Title of theinvention: Footwear with sole which is divided into two parts)

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made keeping in mind theabove problems occurring in the related art, and an objective of thepresent invention is to provide a functional shoe having spaced frontand rear outsoles, the functional shoe providing comfort to a user bybeing flexibly deformed to conform to a shape or walking form of auser's foot during walking, and guiding a tandem gait by allowing afront portion of the foot to be leaned inward while allowing an insideportion of the foot to be leaned inward at the moment when the footcontacts the ground during walking.

In order to achieve the above objective, according to one aspect of thepresent invention, there is provided a functional shoe having spacedfront and rear outsoles, the functional shoe including: a base plateformed in a shape conforming to a foot; an upper body coupled to a lowersurface of the base plate such that a flexible part entirely covering amiddle portion of the lower surface of the base plate is formed, andfront and rear through-holes covering only edges of the lower surface ofthe base plate are formed in front of and behind the flexible part, theupper body being configured to cover the foot to be placed on an upperside of the base plate; and an outsole supporting the foot, andincluding a front outsole coupled to cover the front through-hole, and arear outsole coupled to cover the rear through-hole at a position spacedapart from the front outsole, wherein the front outsole includesmultiple line grooves recessed in an upper surface thereof in a barshape and arranged along a width direction; a bending groove recessedconcavely is formed in a lower surface of the front outsole by extendingtransversely along the width direction at a boundary point between aportion where toes of the foot are located and a portion where a sole ofthe foot is located, and the bending groove is disposed alternately withthe line grooves in a zigzag arrangement; the outsole includes multipleair holes formed in an upper surface thereof at a predetermined depth;and the air holes are provided such that more air holes are formed at apoint of the outsole that supports an inside portion of the sole than apoint that supports an outside portion of the sole.

Furthermore, a conical pivot protrusion may be formed on an outer uppersurface with respect to a center line of the rear outsole, a springgroove may be formed in a lower upper surface with respect to a centerline of the cushioning part, and a spring may be inserted into thespring groove; an upward inclined protrusion having a right-angledtriangular shape in which an inclined surface thereof faces inward ofthe front outsole may be formed on an outer upper surface with respectto a center line of the front outsole, a spring groove may be formed inan inner upper surface with respect to the center line of the frontoutsole, and a spring may be inserted into the spring groove; at frontand rear inner and outer portions of the base plate, a pivot protrusionpassage hole through which the pivot protrusion passes, an inclinedprotrusion passage hole through which the upward inclined protrusionpasses, and spring passage holes through which the front and rearsprings pass, respectively, may be formed through the base plate; and ona lower surface of an insole placed on the base plate in an insertableand detachable manner, a downward inclined protrusion having aright-angled triangular shape in which an inclined surface thereof facesoutward may be formed to protrude downward corresponding to the upwardinclined protrusion.

The functional shoe having spaced front and rear outsoles according tothe present invention as described above can be flexibly deformed toconform to the shape of the foot of walking form of the user due to theprovision of the multiple line grooves formed in the upper surface ofthe front outsole along the width direction thereof. Therefore, thepresent invention can provide an effect of making the user's foot morecomfortable during walking.

In addition, the present invention can guide a tandem gait by allowingthe front portion of the foot to be leaned inward while allowing theinside portion of the foot to be leaned inward at the moment when thefoot contacts the ground during walking. Therefore, the presentinvention can provide an effect of solving a problem caused by anout-toed gait.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objectives, features, and other advantages of thepresent invention will be more clearly understood from the followingdetailed description when taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a side sectional view showing a structure of a functional shoein an exploded state according to a first embodiment of the presentinvention;

FIG. 2 is a bottom view showing the exploded state of the presentinvention shown in FIG. 1;

FIG. 3 is a perspective view showing a lower portion of an upper bodyincluded in the present invention;

FIG. 4 is a bottom view of the present invention shown in FIGS. 1 and 2;

FIG. 5 is a plan view showing an outsole applied to the presentinvention shown in FIGS. 1 and 2;

FIG. 6 is a sectional view taken along line A-A of FIG. 5;

FIG. 7 is a sectional view taken along line B-B of FIG. 5;

FIGS. 8A to 8C are sectional views showing different embodiments of theoutsole taken along line C-C of FIG. 5;

FIG. 9 is an exploded perspective view showing a functional shoeaccording to a second embodiment of the present invention;

FIG. 10 is a sectional view showing a rear outsole side of the presentinvention shown in FIG. 9; and

FIGS. 11A and 11B are sectional views showing an operation relationshipof a front outsole side of the present invention shown in FIG. 9.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, a functional shoe having spaced front and rear outsolesaccording to the present invention will be described with reference tothe accompanying drawings of FIGS. 1 to 11B.

As shown in FIGS. 1 and 2, a functional shoe according to a firstembodiment of the present invention includes: a base plate 100 formed ina shape conforming to a s foot; an upper body 200 having a lower portioncoupled to a lower surface of the base plate 100, and configured tocover the foot to be placed on an upper side of the base plate 100; andan outsole 300 attached to the upper body 200 coupled to the lowersurface of the base plate 100 and configured to support the foot.

The base plate 100 is a portion on which an insole is placed. When theupper body 200 is coupled to the base plate 110 to form a predeterminedshape before the outsole 300 is attached to the upper body 200, the baseplate 100 serves to maintain a bottom shape of the shoe. Therefore, itis preferable that the base plate 100 is formed in such a shape that asole and toes of a user's foot are seated inside the base plate 100 whenthe user wears the shoe according to the present invention.

The upper body 200 may be made of various materials such as leather,synthetic leather, and the like. The upper body 200 is formed in asock-like shape covering the entire foot including the sole, with frontand rear through-holes 220 and 220 b. The front and rear through-holes220 and 220 b are formed at front and rear sides of a lower surface ofthe upper body 200 corresponding to the sole. The front and rearthrough-holes 220 and 220 b are arranged at a spaced apart relationship,with a flexible part 210 interposed therebetween.

As shown in FIGS. 2 and 3, the flexible part 210 is formed at a positioncovering a middle portion of the sole by overlapping opposite lowerportions of the upper body 200. The flexible part 210 includes areinforcement portion 211 padded on a lower surface thereof. Thisconfiguration is to protect the user's foot by preventing a pointedobject from penetrating through a middle portion of the flexible part210 exerting flexibility, the middle portion where the outsole 300 isnot attached.

Accordingly, the upper body 200 is formed in a sock-like shape coveringthe entire foot in which two holes are spaced apart from each other at aportion corresponding to the sole, and the two holes refer to the frontand rear through-holes 220 a and 220 b.

In a state in which the base plate 100 is inserted into the upper body200 formed as above, a portion where an upper surface of a lower portionof the upper body 200 and the lower surface of the base plate 100 faceeach other, i.e., a middle portion facing the edge of the base plate andthe flexible part 210 is attached to the base plate. The front and rearoutsoles 310 and 320 are respectively attached to lower portions of thefront and rear through-holes 220 a and 220 b at positions spaced apartfrom each other, to cover the outer peripheral edges of the front andrear through-holes 220 a and 220 b.

The reinforcement portion 211 may be made of, for example, the samematerial as the upper body 200. Due to the provision of thereinforcement portion 211 padded on the flexible part 210, a paddedportion has an increased thickness, allowing for cushioning (impactabsorption) and also reinforcement of the flexible part 210.

Meanwhile, the outsole 300 includes the front outsole 310 coupled tocover the front through-hole 220 a, and the rear outsole 320 coupled tocover the rear through-hole 220 b. The rear outsole 320 is coupled tothe upper body 200 at a position spaced apart from the front outsole 310by a predetermined interval. Therefore, the front through-hole 220 a andthe rear through-hole 220 b are formed smaller in size than the frontoutsole 310 and the rear outsole 320, respectively.

In addition, as shown in FIGS. 1 and 4, the front outsole 310 and therear outsole 320 may be coupled to the upper body 200 so as to partiallycover the flexible part 210 and the reinforcement portion 211 coveringthe flexible part 210. Due to this, the flexible part 210 formed byoverlapping the opposite lower portions of the upper body 200, and thereinforcement portion 211 padded outside the flexible part 210 arepartially covered and fixed by the outsole 300. This provides an effectof firmly fixing the upper body 200.

The outsole 300 may be made by combining various materials, butpreferably made of a single material such as injection foam rubber thatis elastic, has high wear resistance, light weight, good coldresistance, and excellent moldability in a manufacturing process, thusimproving productivity and economy.

In addition, the outsole 300 may be formed in various shapes, but, asshown in FIGS. 1 and 6 to 8C, may be formed in a concave shape with aprotruding upper edge such that the outsole 300 is coupled to the upperbody 200 while covering a lower side surface of the upper body 200including the base plate 100 therein.

For example, the front outsole 310 may be formed in a concave shape inwhich the front edge and opposite side edges of an upper portionprotrude and a support surface is formed on the inside of the upperportion. The rear outsole 320 may be formed in a concave shape in whichthe rear edge and opposite side edges of an upper portion protrude and asupport surface 321 is formed on the inside of the upper portion.

As shown in FIG. 5, the front outsole 310 applied to the presentinvention includes multiple line grooves 311 recessed in an uppersurface thereof in a bar shape and arranged along a width direction. Theline grooves 311 formed as above allow the front outsole 310 to beflexibly deformed in a longitudinal direction to conform to the shape ofthe foot or walking form of the user. This provides an effect of makingthe user's foot more comfortable during walking.

It is preferable that the line grooves 311 are formed in the supportsurface of the front outsole 310, except for opposite side edge portionsof the front outsole 310 substantially attached to the upper body 200.

In addition, as shown in FIGS. 4 to 6, a bending groove 312 recessedconcavely may be formed in a lower surface of the front outsole 310 byextending transversely along the width direction thereof at a boundarypoint between a portion where the toes are located and a portion wherethe sole is located, which is a point where bending repeatedly occursduring walking.

Herein, one bending groove 312 is shown in FIG. 1, while two bendinggrooves 312 arranged in a spaced apart relationship are shown in FIGS. 4to 6. In the case of forming the two bending grooves, it will be obviousthat the front outsole 310 is bent more flexibly than in the case offorming the one bending groove.

In the case where the bending grooves 312 are formed in the frontoutsole 310 at points where the bending grooves 312 and the line grooves311 correspond up and down, portions between the bending grooves 312 andthe line grooves 311 are thin and tend to be torn when the front outsole310 is repeatedly bent. Therefore, it is preferable that the bendinggrooves 312 formed in the lower surface of the front outsole 310 aredisposed alternately with the line grooves 311 in a zigzag arrangement.

Considering the points where the bending grooves 312 are formed, it ispreferable that one or two line grooves 311 are formed in front of thebending grooves 312 and multiple line grooves 312 are formed behind thebending grooves 312 such that more flexibility is provided to arelatively inflexible portion of the front outsole 310.

Meanwhile, as shown in FIG. 5, the outsole 300 may include multiple airholes 10 formed in the upper surface thereof at a predetermined depth.Each of the air holes 10 includes an empty space formed therein to allowthe outsole 300 to be compressed and stretched in a lateral directionwhen a load is applied to the outsole 300. This configuration improveselasticity, and thus the air holes 10 serve to alleviate a load of theuser's weight transferred to the outsole 300 from the sole.

It is preferable that the air holes 10 are formed at a portion where theload of the user's weight is concentrated while the outsole 300 contactsthe ground. For example, more air holes 10 may be formed at a point ofthe outsole 300 that supports an inside portion of the sole, which isopposite to the blade of the foot (outside portion of the sole), than apoint that supports the blade of the foot.

In describing the present invention, it is to be noted that withreference to the center line that is drawn through the middle of thesole in a front-and-rear direction, an outer portion, which is the bladeof the foot, is referred to as an outside portion of the sole, and aninner portion, which is opposite to the outside portion of the sole, isreferred to as an inside portion of the sole.

In the outsole 300, more air holes 10 are formed at a portioncorresponding to the inside portion of the sole than the outside portionof the sole, and thus a portion corresponding to the inside portion ofthe sole exerts better elasticity. The reason for forming more air holes10 at the portion of the outsole 300 corresponding to the inside portionof the sole is that when the user walks, a larger load is applied to theinside portion of the sole than the outside portion of the sole.

Therefore, when the user walks with the functional shoe according to thepresent invention, when the outsole 300 contacts the ground, an impactload transferred to the outsole 300 from the ground and the load of theuser's weight are alleviated by the elasticity imparted by the air holes10.

In addition, due to the fact that the line grooves 311 are preferablynot formed at points on the upper surface of the front outsole thatcorrespond to the points where the bending grooves 312 are formed, it ispreferable that the air holes 10 are not formed at the points where thebending grooves 312 are formed, i.e., an area between the bendinggrooves 312 and the line grooves 311 adjacent thereto.

Therefore, it is preferable that except for an area between the bendinggrooves 312 and the line grooves 311 adjacent thereto, the air holes 10are formed in the front outsole 310 at areas approximately in front ofor behind the opposite ends of the line grooves 311 where a relativelylarge load is transferred and elasticity is required in a widthdirection of the sole of the user's foot during walking.

Meanwhile, as shown in FIGS. 5 and 7, a cushioning part 322 having apredetermined shape may be formed at a middle portion of the supportsurface 321 of the rear outsole 320. The cushioning part 322 mayprotrude lower than the rear edge and opposite side edges of the upperportion of the rear outsole 320 having a concave shape.

Due to this, the cushioning part 322 is positioned lower than the rearedge and opposite side edges of the upper portion of the rear outsole320, but higher than the support surface 321. The cushioning part 322 isa part to which a relatively large load is transferred at the rearoutsole 320 when a heel of the user's foot is in contact therewith. Thecushioning part 322 has a thicker thickness than the support surface321, thus exhibiting an excellent buffering action during walking. Inaddition, the cushioning part 322 allows only a middle portion of theheel to be in contact therewith during walking. When the foot is liftedoff the ground, the outside of the cushioning part 322 instantaneouslyforms a minute gap with the support surface 321 and pressure is removedfrom the gap, thus providing comfortable walking.

In addition, in the case where the cushioning part 322 protrudes moreexcessively than the support surface 321, the cushioning part 322 mayinterfere with walking. Therefore, it is preferable that the cushioningpart 322 protrudes 0.01 to 0.1 mm more than the support surface 321.

In addition, the cushioning part 322 includes an air line 20 formedalong the edge thereof at a predetermined depth. The air line 20 isconfigured to be elastically compressed when a load is applied to therear outsole 320, thus more efficiently alleviating impact appliedthereto.

Herein, the cushioning part 322 may be configured such that no air line20 is formed at middle portions of the edge thereof and the middleportions are connected to the support surface 321 in oppositedirections. This is to prevent that when the air line 20 is formed alongthe entire edge of the cushioning part 322, the cushioning part 322 isexcessively compressed or distorted by a load acting thereon when theuser's foot contacts the ground.

In addition, the cushioning part 322 may be formed to have a longerlength at the point supporting the inside portion of the sole than thepoint supporting the outside portion of the sole. This is toincreasingly strengthen elasticity toward the inside portion of the solebecause at the heel of the foot, the inside portion of the sole islarger in surface area than the outside portion of the sole and receivesa large load when the foot contacts the ground during walking. Thisensures that abrasion of the rear outsole 320 including the cushioningpart 322 is reduced, and that impact applied to the user's body iselastically alleviated, while guiding the user to walk properly.

Meanwhile, each of the air holes 10 and the air lines 20 may include aninlet open upward, with an air chamber 30 formed in the interior of theoutsole 300 at a lower inside of each of the air hole 10 and the airline 20. The air chamber 30 may be formed in various shapes.

For example, each of the air hole 10 and the air line 20 may be formedin the same width from the inlet to the interior of the outsole 300 inlongitudinal sectional view. Alternatively, as shown in FIGS. 7 to 8C,the air chamber 30 may be formed in the interior of the outsole 300 atthe lower inside of each of the air hole 10 and the air line 20 so as toform a predetermined space that is larger in width than the inlet inlongitudinal sectional view.

Due to the fact that the air chamber 30 forms a wider space than theinlet of each of the air hole 10 and the air line 20, it is ensured thatwhen the outsole 300 is compressed by a load, air present in the airchamber 30 is quickly discharged to the inlet that is relatively narrow.This ensures that air inside the shoe is efficiently circulated whileelastic deformation is made more effectively.

A description will be given of examples in which the air hole 30 isformed in the interior of the outsole 300 at the lower inside of each ofthe air hole 10 and the air line 20. As shown in FIG. 8A, multiple airchambers 30 each of which has a multi-shaped structure may be formed inthe interior of the outsole 300, and an interval between the airchambers 30 may be smaller than the width of each of the air chambers 30such that when the outsole 300 is compressed, air present in each of theair chambers 30 is effectively discharged.

In addition, as shown in FIGS. 8B and 8C, one air chamber 30 may beformed in the outsole 300. As shown in FIG. 8B, the air chamber 30 mayinclude a groove formed smaller than the air chamber 30 at a positionbelow the air chamber 30 such that when the outsole 300 is compressed,air present in the air chamber 30 is dispersed up and down.

The functional shoe according to the present invention described abovecan be flexibly deformed to conform to the shape of the foot or walkingform of the user, thus providing comfort to the user's foot. Inaddition, the present invention can effectively disperse the load of theuser's weight applied to the user's foot when stepping on the ground,thus reducing fatigue during long periods of walking.

Next, a description will be given of a second embodiment of the presentinvention shown in FIGS. 9 to 11B. The second embodiment includes atandem gait-guiding means for guiding an out-toed gait to a tandem gait,in addition to all configurations included in the first embodiment. Adescription of the configurations included in the first embodiment willbe omitted and only the tandem gait-guiding means will be described indetail.

In other words, in the tandem gait-guiding means included in the secondembodiment, a conical pivot protrusion 323 is formed on an outer uppersurface with respect to the center line of a cushioning part 322 formedin a rear outsole 320, and a spring groove 324 is formed in a lowerupper surface with respect to the center line of the cushioning part322. A spring 325 is inserted into the spring groove 324 such that anupper end of the spring 325 protrudes by a height corresponding to atleast the height of an upper end of the pivot protrusion 323.

This configuration in which the upper end of the spring 325 protrudes bya height corresponding to the height of the upper end of the pivotprotrusion 323 is to allow an insole 110 placed on the pivot protrusion323 and the spring 325 to keep level as shown in FIG. 10.

In addition, an upward inclined protrusion 313 having a right-angledtriangular shape in which an inclined surface thereof faces inward of afront outsole 310 is formed on an outer upper surface with respect tothe center line of the front outsole 310, and a spring groove 314 isformed in an inner upper surface with respect to the center line of thefront outsole 310. A spring 315 is inserted into the spring groove 314such that an upper end of the spring 315 protrudes by a heightcorresponding to at least the height of an upper end of the upwardinclined protrusion 313.

This configuration in which the upper end of the spring 315 protrudes bya height corresponding to the height of the upper end of the upwardinclined protrusion 313 is to allow the insole 110 placed on the upwardinclined protrusion 313 and the spring 315 to keep level as shown inFIG. 11A.

In addition, at front and rear inner and outer portions of a base plate100, a pivot protrusion passage hole 101 through which the pivotprotrusion 323 passes, an inclined protrusion passage hole 102 throughwhich the upward inclined protrusion 313 passes, and spring passageholes 103 and 104 through which the front and rear springs 315 and 325pass, respectively, are formed vertically through the base plate.

The base plate 100 is a part that is inserted into an upper body 200. Ina state where the upward inclined protrusion 313, the pivot protrusion323, the front and rear springs 315 and 325 pass through the inclinedprotrusion passage hole 102, the pivot protrusion passage hole 101, andthe front and rear spring passage holes 103 and 104, respectively, alower surface of the base plate 100 is attached to a lower portion ofthe upper body 200 and upper portions of the front and rear outsoles 310and 320, the lower surface of the base plate facing the same.

The lower portion of the upper body 200 to which the lower surface ofthe base plate 100 is attached is a portion except for front and rearthrough-holes 220 a and 220 b, which refers to the outer edges of frontand rear through-holes 220 a and 220 b and an upper surface of aflexible part 210, i.e., a portion facing an upper surface of the baseplate 100. It is natural that the front and rear outsoles 310 and 320and the base plate 100 are attached to each other in empty spaces of thefront and rear through-holes 220 a and 220 b where the front and rearoutsoles 310 and 320 and the base plate 100 face each other.

In addition, at the center of a lower surface of the insole 110 placedon the base plate 100 in an insertable and detachable manner, an elasticplate 112 is provided in a longitudinal direction to allow the insole110 to maintain a predetermined strength in a horizontal direction whilebeing freely bent in a vertical direction. On the lower surface of theinsole 110 facing the upward inclined protrusion 313, a downwardinclined protrusion 111 having a right-angled triangular shape in whichan inclined surface thereof faces outward is formed to protrude downwardcorresponding to the upward inclined protrusion 313.

Herein, the elastic plate 112 is formed in a curved shape incross-section like an elastic tape. As shown in FIGS. 11A and 11B, it ispreferable that the elastic plate 112 is attached to the lower surfaceof the insole 110, with a concave portion thereof facing upward, suchthat the insole 110 is easily bent upward. It is further preferable thatcoupling of the insole 110 and the elastic plate 112 is realized viarivets 113 that engage front and rear ends of the elastic plate 112 tothe insole 110.

As shown in FIG. 10 to FIG. 11B, in the present invention according tothe second embodiment configured as described above, before wearing thefunctional shoe according to the present invention, the insole 110 is ina horizontal state in which the insole 110 is spaced above the baseplate 100 at a predetermined interval. In this horizontal state, theinsole 110 is placed on the pivot protrusion 323 and the spring 325 atthe rear outsole 320 side, while being placed on the upward inclinedprotrusion 313 and the spring 315 at the front outsole 310 side.

In this state, when the user starts to walk with the functional shoeaccording to the present invention, when the user's foot is lifted abovethe ground, the load of the user's weight does not act on the lower sideof the shoe, and thus the insole 110 is in the horizontal state due tothe elasticity of the springs 315 and 325 acting thereon.

When the user's foot is lifted above the ground in this way and thencontacts the ground during walking, the heel contacts the ground first,and the insole 110 is pressed by a load generated when the heel contactsthe ground first.

When a load is applied to the insole 110, the pivot protrusion 323supporting a lower portion of the insole 110 is compressed only by anamount corresponding the cushion amount of the material forming the rearoutsole 320. However, due to the spring 325 which is smaller incompressive strength than the rear outsole 320, the insole 110 is leanedinward with respect to the center line of the rear outsole 320 in whichthe spring 325 is provided, and the heel of the user's foot is alsoleaned inward with respect to the center line.

When the middle portion of the foot contacts the ground instantaneouslyafter the heel contacts the ground in this way, the sole is bent andflexed instantaneously because the shoe according to the presentinvention has no outsole at the middle portion thereof but the flexiblepart 210 of the upper body 200. This allows the upper body 200 includingthe flexible part 210, the base plate 100, and the middle portion of theinsole 110 to be bent flexibly, thus providing comfort to the solewithout restraint.

After the middle portion of the sole contacts the ground instantaneouslyin this way, a front portion of the foot contacts the ground. At themoment when the heel contacts the ground, as the heel is leaned inwardwith respect to the center line of the rear outsole 320 in which thespring 325 is provided, the front portion of the foot is also leanedinward, with the foot leaned, and contacts a front portion of the insole110.

When the front portion of the sole contacts the front portion of theinsole 110 in this way, due to the fact that the spring 315 supports theinsole 110 on the inside with respect to the center line at the frontportion of the insole 110 in a state where the inclined protrusion 313and the downward inclined protrusion 111 face each other on the outsidewith respect to the center line, as the spring 315 is lowered, the frontportion of the sole that is in contact with the insole 110 is leanedinward with respect to the center line.

When the front portion of the sole is leaned inward with respect to thecenter line, due to the fact that the inclined surface of the upwardinclined protrusion 313 is formed to be inclined downward and inward ata lower portion of the outside with respect to the center line in astate where the upward inclined protrusion 313 and the downward inclinedprotrusion 111 face each other, the inclined surface of the downwardinclined protrusion 111 slightly slides downward along the inclinedsurface of the upward inclined protrusion 313 due to a load acting onthe insole 110.

In a state where the foot is leaned inward from the heel and then thefront portion of the sole is also leaned inward as above, as the insole110 is slightly lowered inclinedly along the inclined surface of theupward inclined protrusion 313, the front portion of the sole isslightly leaned inward with respect to the center line.

Through such a mechanism that the foot is instantaneously leaned inwardfrom the heel to the front portion of the sole, the user who walks withan out-toed gait is guided to walk with a tandem gait.

In addition, the insole 110 is typically made of a soft material becausethe sole is in direct contact therewith. In the present invention, duethe fact that the insole 110 included in the tandem gait-guiding meanshas to be leaned inward, and that the shoe according to the invention ischaracterized by the middle portion thereof that is flexibly bendable,the insole 110 has to exert stiffness to some extent.

Therefore, the elastic plate 112 is provided longitudinally at thecenter of the lower surface of the insole 110 in a curved shape incross-section like an elastic tape to allow the lower surface of theinsole 110 to maintain stiffness, with the concave portion of theelastic plate 112 facing upward.

Due to the provision of the elastic plate 112 as above, the elasticplate 112 is flexibly bent upward, but is not easily bent downward andis not folded in a lateral horizontal direction. Therefore, it isensured that the elastic plate 112 is leaned inward withoutinterference, that the front portion of the elastic plate 112 is twistedby a predetermined angle without interference to allow the insole 110 tobe leaned inward, and that the front portion of the insole 110 is leanedinward without interference when lowered along the inclined surface ofthe upward inclined protrusion 313. It is further ensured that themiddle portion of the sole is bent and flexed without interference.

Although exemplary embodiments of the present invention have beendescribed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

What is claimed is:
 1. A functional shoe having spaced front and rear outsoles, the functional shoe comprising: a base plate (100) formed in a shape conforming to a foot; an upper body (200) coupled to a lower surface of the base plate (100) such that a flexible part (210) entirely covering a middle portion of the lower surface of the base plate (100) is formed, and front and rear through-holes (220 a and 220 b) covering only edges of the lower surface of the base plate (100) are formed at in front of and behind the flexible part (210), the upper body being configured to cover the foot to be placed on an upper side of the base plate (100); and an outsole (310) supporting the foot, and including a front outsole (310) coupled to cover the front through-hole (220 a), and a rear outsole (320) coupled to cover the rear through-hole (220 b) at a position spaced apart from the front outsole (310), wherein the front outsole (310) includes multiple line grooves (311) recessed in an upper surface thereof in a bar shape and arranged along a width direction, a bending groove (312) recessed concavely is formed in a lower surface of the front outsole (310) by extending transversely along the width direction at a boundary point between a portion where toes of the foot are located and a portion where a sole of the foot is located, and the bending groove is disposed alternately with the line grooves (311) in a zigzag arrangement, the outsole (300) includes multiple air holes (10) formed in an upper surface thereof at a predetermined depth, and the air holes (10) are provided such that more air holes are formed at a point of the outsole (300) that supports an inside portion of the sole than a point that supports an outside portion of the sole.
 2. The functional shoe of claim 1, wherein the air holes (10) are formed in the front outsole (310) at areas approximately in front of or behind opposite ends of the line grooves (311), except for an area between the bending groove (312) and the line grooves (311) adjacent thereto.
 3. The functional shoe of claim 1, wherein the rear outsole (320) is formed in a concave shape in which a rear edge and opposite side edges of an upper portion protrude and a support surface (321) is formed on an inside surface of the upper portion, and a cushioning part (322) having a predetermined shape is provided at a middle portion of the support surface (321) by protruding lower than the rear edge and opposite side edges of the upper portion of the rear outsole (320).
 4. The functional shoe of claim 3, wherein the cushioning part (322) is configured such that middle portions of an edge thereof are connected to the support surface (321) in opposite directions and an air line (20) is formed along a remaining portion of the edge at a predetermined depth.
 5. The functional shoe of claim 4, wherein each of the air holes (10) and the air line (20) includes an air chamber (30) formed in an interior of the outsole (300) to form a predetermined space that is larger in width than an inlet in longitudinal sectional view.
 6. The functional shoe of claim 3, wherein the cushioning part (322) is formed to have a longer length at the point that supports the inside portion of the sole than the point that supports the outside portion of the sole.
 7. A functional shoe having spaced front and rear outsoles, the functional shoe comprising: a base plate (100) formed in a shape conforming to a foot; an upper body (200) coupled to a lower surface of the base plate (100) such that a flexible part (210) entirely covering a middle portion of the lower surface of the base plate (100) is formed and front and rear through-holes (220 a and 220 b) covering only edges of the lower surface of the base plate (100) are formed in front of and behind the flexible part (210), and configured to cover the foot to be placed on an upper side of the base plate (100); and an outsole (310) supporting the foot, and including a front outsole (310) coupled to cover the front through-hole (220 a), and a rear outsole (320) coupled to cover the rear through-hole (220 b) at a position spaced apart from the front outsole (310), wherein the front outsole (310) includes multiple line grooves (311) recessed in an upper surface thereof in a bar shape and arranged along a width direction, a conical pivot protrusion (323) is formed on an outer upper surface with respect to a center line of the rear outsole (320), a spring groove (324) is formed in a lower upper surface with respect to a center line of the cushioning part (322), and a spring (325) is inserted into the spring groove (324), an upward inclined protrusion (313) having a right-angled triangular shape in which an inclined surface thereof faces inward of the front outsole (310) is formed on an outer upper surface with respect to a center line of the front outsole (310), a spring groove (314) is formed in an inner upper surface with respect to the center line of the front outsole (310), and a spring (315) is inserted into the spring groove (314), at front and rear inner and outer portions of the base plate (100), a pivot protrusion passage hole (101) through which the pivot protrusion (323) passes, an inclined protrusion passage hole (102) through which the upward inclined protrusion (313) passes, and spring passage holes (103 and 104) through which the front and rear springs (315 and 325) pass, respectively, are formed through the base plate, and on a lower surface of an insole (110) placed on the base plate (100) in an insertable and detachable manner, a downward inclined protrusion (111) having a right-angled triangular shape in which an inclined surface thereof faces outward is formed to protrude downward corresponding to the upward inclined protrusion (313).
 8. The functional shoe of claim 7, wherein the spring (325) is provided such that an upper end thereof protrudes by a height corresponding to a height of an upper end of the pivot protrusion (323), and the spring (315) is provided such that an upper end thereof protrudes by a height corresponding to a height of an upper end of the upward inclined protrusion (313), and an elastic plate (112) is provided at a center of the lower surface of the insole (110) in a longitudinal direction, the elastic plate (112) is formed in a curved shape in cross-section, and front and rear ends of the elastic plate (112) are engaged to the insole (110) by rivets (113), with a concave portion of the elastic plate facing upward. 